(1) Simplest low-pass FIR filter example

Define impulse response sequence

Frequency response function

Frequency response function

Plots of frequency response function as a function of θ

Output of system for simple cosine input: time-domain convolution

Sampling frequency

Part of input sequence

Output of system for simple cosine input: use frequency-response function

Value at 50Hz (θ = 2π 50/= 0.2π)